Llanelli Old Castle

Has been described as a Certain Timber Castle (Motte)

There are earthwork remains

NameLlanelli Old Castle
Alternative NamesCarnwyllion; Castle of Carnwillion; Yr hen gastell
Historic CountryCarmarthenshire
Modern AuthorityCarmarthenshire
1974 AuthorityDyfed

Claimed as partially submerged motte of earthwork castle, although some uncertainty surrounds this identification and the monument has also been described as a 'tumulus'. A bailey is said to be visible when water levels in the reservoir are low. (Coflein)

Monument comprising the remains of a medieval motte and bailey castle partially submerged within the reservoir of the former Old Castle Tinplate works. Roughly 30m in diameter. Motte identified as the likely site of the historic Castle of Carnwyllion, destroyed by Rhys Ieuanc of Dinefwr (d.1222) during his attack on Kidwelly and the Gower in 1215. (Dyfed Archaeological Trust HER)

An early mound castle unquestionably stood at Llanelly, the name of which has fortunately survived and led to the identification of the site. In the upper part of the town is a tin plate manufactory called Old Castle Works, and an adjoining farm is called Old Castle Farm. Within the bounds of the former is a large and fairly deep reservoir in which the mound is almost submerged, leaving only 6 to 8 feet of the top projecting above the water at its normal level, but it is credibly reported that when the water is low the lines of a base court are distinctly discernible. The mound is described as having been about 20 feet high, with a ditch round it, and entirely grass grown. It has been dug into on the eastern side, probably when the bank for the feeder of the reservoir was made. It is referred to in one of die Fenton Mss. in the Cardiff Municipal Library as ‘Yr hen gastell.’ Mention is also made of ‘Y Domen Fawr,’ or ‘Tumulus, by the Hen Gastell,’ which is sufficient to indicate its general character. (RCAHMW 1917)

The monument comprises the remains of a medieval motte and bailey castle. The mound measures roughly 30m in diameter; it is partially submerged within the reservoir of the former Old Castle Tinplate works

The motte has been identified as likely site of the historic Castle of Carnwyllion, destroyed by Rhys Ieuanc of Dinefwr (d. 1222) during his attack on Kidwelly and the Gower in 1215. (Scheduling Report)

Gatehouse Comments

Shown on the six-inch OS map of 1878 before the creation of the resevoir as a flat topped circular mound surronunded by a wide ditch at the neck of a meander in the river. See also Llanelli New Castle.

- Philip Davis

This site is a scheduled monument protected by law

Not Listed

The National Monument Record (Coflein) number(s)
County Historic Environment Record
OS Map Grid ReferenceSN500003
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  • Morgan, Gerald, 2008, Castles in Wales: A Handbook (Talybont: Y Lolfa Cyf.) p. 253 (listed as possible)
  • Pettifer, Adrian, 2000, Welsh Castles, A Guide by Counties (Boydell Press) p. 58
  • Davis, Paul, 2000, A Company of Forts. A Guide to the Medieval Castles of West Wales (Gomer Press) p. 35
  • Salter, Mike, 1996, The Castles of South West Wales (Malvern) p. 37
  • Davis, P.R., 1987, Castles of Dyfed (Llandysul: Gomer Press) p. 69
  • King, D.J.C., 1983, Castellarium Anglicanum (London: Kraus) Vol. 1 p. 57
  • Fry, P.S., 1980, Castles of the British Isles (David and Charles) p. 362
  • Renn, D.F., 1973 (2 edn.), Norman Castles of Britain (London: John Baker) p. 228
  • RCAHMW, 1917, An inventory of the Ancient Monuments of Carmarthenshire (HMSO) p. 119 no. 349 online copy


  • Davies, J D., 1982, ‘The castle of Carnwyllion’, The Carmarthen Antiquary Vol. 18 p. 29–36
  • Hogg, A.H.A. and King, D.J.C., 1963, 'Early castles in Wales and the Marches: a preliminary list' Archaeologia Cambrensis Vol. 112 p. 77-124
  • Brown, R, Allen, 1959, 'A List of Castles, 1154–1216' English Historical Review Vol. 74 p. 249-280 (Reprinted in Brown, R. Allen, 1989, Castles, conquest and charters: collected papers (Woodbridge: Boydell Press) p. 90-121) view online copy (subscription required)

Primary Sources

  • Brut y Tywysogion 1190, 1201, 1215 (Carnwillion) (Several transcriptions and translations exist the best being Jones, T., 1952, Brut Y Twysogion (University of Wales, History and Law series 11)–based on the Peniarth MS 20 version. There is a flawed translation Williams ab Ithel, John, 1860, Brut Y Twysogion or The Chronicle of the Princes (Rolls Series) online copy)